Generally, attempts to improve the fuel efficiency of construction machines have been made.
Furthermore, a construction machine is equipped with an energy storage device, and auxiliary power is implemented using energy stored in the energy storage device. The auxiliary power enables the load of an engine to be reduced.
Meanwhile, each engine has different dynamic characteristics. In particular, the optimum fuel efficiency of such an engine may vary depending on specific engine revolutions per minute (RPM).
However, according to a conventional technology, although in a conventional construction machine, a load imposed on an engine can be reduced by auxiliary power and thus engine RPM can be changed, the conventional construction machine is problematic in that it cannot implement optimum fuel efficiency corresponding to the changed engine RPM.